how can I set several IPs for one domain?

I set a valid IP for my domain. now I need to set an invalid one for internal users. I set it and set a "www" DNS record to point to this IP. But when I enter www.mydomain.com, I get
"his IP address is shared. For access to the web site which you look for, enter its address instead of its IP."
error.
by typint "mydomain.com" (without www prefix) it works properly.

i really dont understand the coding, but i do have a question, say for example like Yahoo. yahoo have several servers all over the world and it manages all the servers in a single domain that is yahoo.com or yahoo.co.in. what does it do on the server site to manage the mail comming to the different-2 servers at the same domain name yahoo.com?
John

In ISPC2 websites must be configured for one address or another not both. Apache has the ability to do this but that would require Apache and the site to listen on all addresses. If you were to change these settings manually then the next time you make a change in ISPC2 your changes would be over written.

If what you are trying to accomplish is to have access to the website that has a public address from your private network then this is a function of your firewall/router not the web server.

The example below shows a small map of data flow and the path that your connections would make.

Yes you're right, you have to add the address 10.1.1.25 to ISPConfig and then change the private site to that address.

You can do that by following the steps:

1. Logon to ISPConfig and go to the Management tab.
2. Go to Server and then Settings
3. Add the new IP (10.1.1.25) in the IP list and click Save.
4. Go back to the ISP Manager tab and locate your website.
5. In your website, click the IP Address drop down menu and select the new IP and click Save.

When ISPConfig updates Apache then your new website will be accessible inside the network. One note of caution though. you don't want the private site's DNS to display the private address to the public. The less hackers know about your network the better.